Conventionally, in a packaging-container manufacturing apparatus which manufactures packaging containers each containing food having fluidity (for example, liquid food) such as milk or juice, a weblike packaging material manufactured by means of a packaging-material manufacturing apparatus is set in the form of a reel in a dispenser section of a filling machine, and is dispensed and transferred through the filling machine in synchronism with supply of a liquid food. The packaging material is a flexible laminate including a paper substrate, and films of polyethylene resin covering opposite surfaces of the paper substrate. When necessary, a barrier layer, formed of aluminum foil, gas barrier resin, or the like, is formed between the paper substrate and the films.
After being dispensed from a dispenser, the packaging material is sealed longitudinally to thereby be formed in a tubular shape, and the liquid food is charged from a supply pipe into a tubular packaging material.
Incidentally, when the packaging material is formed in a tubular shape, opposite edges of the packaging material form steps inside and outside the tubular packaging material. If the liquid food soaks into packaging material from an end surface of the packaging material which forms the inside step as a result of the liquid food being charged into the tubular packaging material, the quality of packaging containers deteriorates.
In order to overcome the above-described problem, an elongated strip tape is bonded across the step so as to prevent the end surface of the packaging material from coming into contact with the liquid food (see, for example, Patent Document 1).
Patent Document 1: Japanese Patent Application Laid-Open (kokai) No. H7-315363.